1. Field of the Invention
The present invention relates to a dual-shaft synchronous motion device, and more particularly to a pivot shaft in cooperation with rotors and a tractive member so that first and second shafts are turned synchronously.
2. Description of the Prior Art
A pivot or a turning shaft which can be turned back and forth by applying an external force is widely used to en electronic article, such as a cell phone, a notebook, a PDA, a digital camera, an electronic book and the like, so that its cover, display screen, or a watch window can be turned to open/close. For example, Taiwan Patent No. 97222022 discloses a turning shaft structure; Taiwan Patent No. 96217011 discloses a pivot positioning structure; and Taiwan Patent No. 98207366 discloses a pivot structure.
For the display module (such as, a screen) and/or the machine body module of the electronic article to provide more operation modes and applied range, the prior art also discloses a dual shaft disposed between the display module and the machine body module. For example, Taiwan Patent No. 96148572 discloses a super-wide angle dual turning shaft structure; Taiwan Patent No. 99211350 discloses a dual pivot hinge.
Regarding the operation, motion and configuration of the prior art, the pivot or turning shaft assembly usually includes a plurality of through holes, concave and convex spacers for positioning, friction plates and springs which are assembled to the turning shafts. Two ends of the turning shaft are respectively positioned by buckles or fixtures. The turning shaft or pivot assembly is turned and positioned by the springs to store and release energy.
The prior art also discloses a dual-shaft device. A first shaft and a second shaft are respectively provided with a cam which is driven by the first and second shafts. A movable latch is provided between the two cams of the first and second shafts. When the first shaft is turned, the cam of the first shaft will push the latch to block the cam of the second shaft so that the second shaft cannot be turned. After the first shaft is turned 180 degrees, the second shaft can be turned with its cam to push the latch to block the cam of the first shaft.
The first and second shafts of the aforesaid structure cannot be turned synchronously. After the first shaft is turned to be positioned, the second shaft can be operated accordingly. When the cam is turned to push the latch to block another cam, there is a noise. When the first and second shafts are turned to be positioned, a block of the cam is against a positioning portion of the dual-shaft device. Thus, during operation, there will be a collision between the parts when positioned or it will be stopped by the positioning portion. These situations are not expected.
Typically, if the configuration of the turning shaft and the related parts can be changed, it will be used widely and convenient for assembly.
According to the aforesaid, the topics to consider the design of configuration and the techniques are as follows:
1. Providing a synchronous motion device disposed between the display module and the machine body modules. When the display module is turned 0-180 degrees, the machine body module will be relatively turned 0-180 degrees. The total turning angle of the display module and the machine body module can achieve 360 degrees. Under the condition that the electronic product has various operation modes (or applied range), it provides an easy and convenient operation effect.
2. The synchronous motion device should remove the through holes, the concave and convex spacers for positioning, the friction plates and the springs. The turning shaft or pivot assembly is turned and positioned by the springs to store and release energy. The aforesaid patents don't teach or disclose these topics.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.